All the subjects will undergo a TST and QFT-G test A 2-TU dose of PPD will be administered by a certified technician using the Mantoux method and induration measured after 72 h. TST will be deemed positive if bove or equally to 5 mm for RA patients and 10 mm for controls The absence of induration of <2 mm in diameter will be recorded as anergic and negative TST results was defined as having more than 2 but less than 5 mm reactions for RA patients.